This invention relates to a padlock of the kind comprising a lock body, a lock shackle movable between locking and releasing positions, and, inside the lock body, bolt means for securing and releasing the shackle in its locking position and a cylinder lock mechanism for controlling the bolt means.
Padlocks are produced in different sizes and forms and can be equipped with different kinds of lock shackles depending on their intended use and required strength properties. Generally each lock manufacturer produces its own lock bodies and lock mechanisms designed for particular uses. Different manufacturers have cylinder locks of different sizes and forms depending on the traditions of lock manufacturers and the practice and norms of different marketing areas. Because of these factors it has not generally been possible to use, for a given design of lock body, different cylinder lock mechanisms providing a series of padlocks of similar appearance but having different intended uses or different geographical areas of use. Instead each manufacturer generally produces a different padlock body for each cylinder lock type.
Padlocks of the kind referred to and having replaceable lock mechanisms are known from U.S. Pat. No. 3,835,675 and U.S. Pat. No. 4,545,223. Such known padlocks can be operated with different keys by changing the opening combination of the lock mechanism, for example by replacing the whole cylinder lock with another similar type.
One aim the present invention is to simplify the production and assembly of padlocks so that the same padlock body can be used for different kinds of cylinder lock types. In this way norms and practices of different countries can be taken account of in a better and simpler manner than before whilst allowing the benefits of mass-production to be achieved. It is also an aim of the invention to provide a padlock having improved burglarproof features.
With a padlock embodying the present invention it is possible to make use of the same lock body with different cylinder lock types. Additionally, due to its casing-like construction, the fixing unit protects the cylinder lock mechanism better than other known releasable cover elements.
It is possible to choose according to the requirement of the padlock the material from which the fixing unit is made. Advantageously the material chosen for the fixing unit will be different from the material of the lock body and/or the cylinder lock mechanism. For example the fixing unit may be made from chilled steel. In this the cylinder lock mechanism itself, or particularly its cylinder and other locking device parts, can be fabricated from cheaper material, without sacrificing the burglarproof properties of the padlock. The same applies also to the padlock body itself which can be made, for example, from brass if the intended use does not require the padlock to be made of steel.
If the guiding surfaces of the fixing unit are formed so that they guide two or several different kinds of cylinder lock mechanisms, the same fixing unit can be used correspondingly for different kinds of lock cylinder mechanisms. In this manner the amount of different stock items can be reduced.
The fixing unit is most favourably formed so that its dimension in a plane perpendicular to the axial direction of the cylinder lock mechanism is essentially greater than its dimension in this axial direction. In this case it can be equipped in practically all issued cylinder lock types, for example with tumbler locks or so called DIN-norm locks and despite of that the basic form of the padlock can be held quite flat.
The fixing unit is able to support different types of lock mechanism. Thus many different types of padlock, each having the same lock body, can be created. Also by providing different fixing units, whose inner guiding surfaces are different and which support different lock mechanisms, even more padlock types can be created for the same lock body.
According to another aspect of the invention there is provided a padlock arrangement as claimed in the ensuing claim 6.